Rotary printer for use in conjuction with an indexed conveyor

ABSTRACT

A rotary printer for printing articles advanced step-by-step by a conveyor and thermoformable sheets carried thereby. The printer has a base in support of a carriage and includes structure to reciprocate the carriage relative to the base a predetermined distance lengthwise of the conveyor. The carriage has a rotatable member including at least one arcuate blanket portion that may include sections, one form roll for each color to be printed and for each blanket portion, and an ink distributor for each form roll. Structure is provided to rotate the rotatable member in the same direction in both directions of carriage travel, one direction being the printing direction with the blanket portion or portions engaging the article or articles or the thermoforable sheet and, in the other direction, each blanket portion being returned to a predetermined starting position and, by then, being at least partially re-inked by rolling engagement with a form roll. Where more than one other form roll is provided for each blanket portion, each blanket portion is re-inked by its rolling engagement therewith so that most of the re-inking is effected in the return stroke. When a blanket portion is a minor arc, the rotatable member is turned at such an increased rate in the inking direction that it is always in its predetermined starting position at the end of the travel of the carriage in its return or inking direction. The printer may be incorporated in a thermoformer.

United States Patent 1191 Snow et afl. 1 Aug. 6, 1974 ROTARY PRINTER FOR USE IN Primary ExaminerRobert E. Pulfrey CONJUCTION WITH AN INDEXED Assistant ExaminerClifford D. Crowder CONVEYOR [76] Inventors: Gerald A. Snow, 5 Pine Ridge Rd., [57] E S Q Cumberland Foreside Maine; A rotary printer for prmtmg art1cles advanced step-by- Vladimir orlovsky, 691 High St step by a conveyor and thermoformable sheets carried Bath, Maine 04530 thereby. The printer has a base in support of a car- I riage and includes structure to reciprocate the car- Filed? g 23,1972 riage relative to the base a predetermined distance [2]] Appl 283,056 lengthwise of the conveyor. The carriage has a rotatable member including at least one arcuate blanket Relaied Application Data portion that may include sections, one form roll for [63] Continuation-impart of Ser. No. 192,190, Oct. 26, each color to be printed and for each blanket portion, 1971, abandoned. and an ink distributor for each form roll. Structure is provided to rotate the rotatable member in the same Cl direction in both directions of carriage travel, one di- 10l/282, 264/ 132 rection being the printing direction with the blanket [51] Int. Cl. B4 17/00, B4if 3/58 portion or portions engaging the article or articles or Field Of Search 101/35, the thermoforable sheet and, in the other direction,

/2 126, 425/302; each blanket portion being returned to a predeter- 153 mined starting position and, by then, being at least partially re-inked by rolling engagement with a form References Cited roll. Where more than one other form roll is provided UNITED STATES PATENTS for each blanket portion, each blanket portion is re 1 302,366 4/1919 Hodgman, 1r. 101/282 inked by its rolling engagement therewith so that most 1:437,461 12 1922 Annand 101 272 of the ro-inkiflg is effected in the return Stmkewhen 1,683,774 9/1928 Haase 101/35 a ank t p t n is a minor a the tata member 2,166,138 7/1939 Gundlach 101/35 is turned at such an increased rate in the inking direc- 2,697,398 12/1954 Pollock lOl/282 tion that it is always in its predetermined starting posi- 2,997,948 8/196] Scheeler fit 8i. 101/126 tion at the end of the travel of the arriage in its re- 22: 3 g 3% turn or inking direction. The printer may be incorpo- 3:654:856 4/1972 Olsen 101/126 x rated m a thermoformer' 15 Claims, 27 Drawing Figures PATENTEDMIB 61914 3.827. 356

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sum 11 or 1a PAIENTED mc 61914 sum 1| or1a ROTARY PRINTER FOR USE IN CONJUCTION WITH AN INDEXEI) CONVEYOR This application is a continuation-in-part of Ser. No. 192,190, filed Oct. 26, 1971, now abandoned.

BACKGROUND OF THE INVENTION In the production of many articles, it is desirable that they be printed, often with a plurality of colors, while they are being conveyed on an indexed conveyor.

As an example of the problem with which the invention is concerned, various articles can be produced from foamed plastic sheets at high rates using thermoformers having heating, forming and blanking stations and step-by-step conveying means for advancing the sheet material from station-to-station. As shown in U.S. Pat. No. 3,504,074, such thermoformers may be provided with printing stations utilizing printing means of the letter press type to print the articles before the blanking station is reached.

The use of that type of printing means has not been entirely satisfactory in a number of respects. Multiple units are required when different colors are to be printed and their operation is relatively slow. In addition, the desired quality of printing is not always attained due to such factors as that letter presses are essentially limited to character printing and that the thickness of the material in the area to be printed may vary slightly and thus affect the quality of the printing even though such variations are of no consequence when considering the appearance or functioning of the articles.

In addition, articles are also formed from thermoformable sheets of plastic that are sufficiently inert to avoid such problems as shrinkage that are encountered in thermoforrning articles from foamed plastic sheets. One such plastic, by way of example, and not by way of limitation, is high impact polystyrene. The present practice is to print such materials as a separate operation with the rolls of printed materials being transferred to the thermoformer to be fed therethrough thus to enable the sides of containers and their covers to be printed which is not possible if their printing is effected after the articles are formed in the sheets.

THE PRESENT INVENTION The general objective of the present invention is to provide rotary printers that can be used in conjunction with an indexed conveyor that positively advances articles or sheet materals into a predetermined position and that are adapted to print different colors simultaneously without imposing limitations on dwell periods and with a higher quality of printing resulting than has hitherto been obtainable.

The above objective is attained by providing a carriage with a rotatable member having at least one arcuate blanket portion of greater radial extent than the remainder of that member, at least one form roll for each blanket portion and tangent with its path, means to deliver ink to each form roll, and a drive for each form roll and the ink delivering means'and connected to the rotatable member. The carriage is mounted over the conveyor and is provided with means to reciprocate it through a predetermined stroke. In one direction of the travel of the carriage and during a dwell, the arcuate blanket portion or portions roll against the surface of the sheet material or its article or articles formed therein that are to be printed and in the other direction of the carriage travel, but not necessarily during a dwell, the blanket portion or portions are returned to a predetermined starting position above the sheet material and out of the path of the articles and, by then, at least partially re-inked by rolling engagement with the appropriate form roll or rolls. The rotatable member is rotated as an incident of its reciprocation. Unless an arcuate blanket portion is in extent, or if its direction of rotation is reversed during the reset travel of the carriage, the rate of rotation of the blanket portion in the reset travel of the carriage is sufficiently increased to ensure that said arcuate blanket portion is in said predetermined starting position for printing at the beginning of each dwell.

A PREFERRED EMBODIMENT OF THE INVENTION In the accompanying drawings illustrating preferred embodiments of the invention:

FIG. 1 is a side view of apparatus incorporating a rotary printer in accordance with the invention;

FIG. 2 is a side view of the printing station and the printer;

FIG. 3 is a partly sectioned view of the printer taken from its forward end but with the form rolls and ink distributors removed;

FIG. 4 is a plan view of the base of the printer;

FIG. 5 is a fragmentary side view of the base of the printer showing the vertically reciprocable rack frame and the carriage gears;

FIG. 6 is a section taken approximately along the indicated lines 6-6 of FIG. 5;

FIG. 7 is a side view of one of the backing forms and the means operable to raise and lower it;

FIG. 8 is an end view thereof;

FIG. 9 is a section, on an increase in scale, taken approximately along the indicated lines 9-9 of FIG. 8;

FIG. 10 is a schematic view illustrating the position of the arcuate blanking portion in its starting position;

FIG. 11 is a like view illustrating the position of the blanking portion in rolling contact with an article;

FIG. 12 is a like view but illustrating the blanket portion at the end of a printing stroke;

FIG. 13 is another similar view but illustrating the inking of the blanket portion during its return;

FIG. 14 is a fragmentary side view of the carriage showing one of the form rolls and the ink distributor therefor with an end wall of the distributor broken away to show the gearing;

FIG. 15 is a like view but with the distributor broken away to show the several rolls;

FIG. 16 is a section taken approximately along the indicated lines 16-16 of FIG. 14;

FIG. 17 is a partly sectioned view of a form roll unit as seen from its rear;

FIG. 18 is a view of an ink distributor as seen from the end opposite to that illustrated by FIG. 14;

FIG. 19 is a partly sectioned top plan view of an ink distributor with the ink fountain removed;

FIG. 20 is a plan view of the index station of the apparatus;

FIG. 21 is a partly sectioned side view of one of the chain locking devices at the index station;

FIG. 22 is a side view of one of the chain grabbing devices of the indexing means; 

1. A rotary printer for use in conjunction with a step-by-step conveyor in printing, during dwells, the upper surfaces of the portions of long lengths of thermoplastic sheet material or of articles formed therein that are exposed during a dwell, said printer comprising a carriage, means to reciprocate said carriage through a predetermined stroke over said conveyor from a predetermined starting position, said carriage including a rotatable member provided with an arcuate blanket portion engageable with the surface to be printed and of a radius greater than the remainder of the member, of a width eQual to the width of the surface to be printed and of a length equal to the length of the surface of the material to be printed during a dwell, means to rotate said member as an incident of its reciprocation but always in the same direction, said carriage also including at least one form roll tangent with the path of said arcuate portion, means to deliver ink to said form roll, and a drive for said form roll and said ink delivery means connected to said rotatable member, said blanket portion in one direction of carriage travel rolling against the surface to be printed and in the other direction of carriage travel being returned to a said starting position with the blanket portion disposed away from the the conveyor for engagement with said form roll to be at least partially inked by rolling engagement therewith when it is at said starting position, and means to initiate the operation of said reciprocating means through a complete stroke at the start of each dwell and effecting at least said one direction of travel during that dwell.
 2. The rotary printer of claim 1 in which the blanket portion defines a minor arc and the means rotating the member effects the rotation thereof at a sufficiently higher rate in the return direction of the carriage to place the blanket portion in said starting position at the end of the travel of the carriage in said return direction.
 3. The rotary printer of claim 1 in which the printer includes supporting structure, means connecting the carriage to the structure laterally of the conveyor for movement relative thereto through said predetermined stroke and the member rotating means includes gear means rotatable with the rotatable member of the carriage, first and second rack portions extending lengthwise of the path of the carriage, and means to effect relative vertical movement between said racks as a unit and said carriage between limits, said rack portions being disposed for engagement with the gear means in the alternative, one rack portion in one direction of carriage travel at one of said limits and the other rack portion in the other direction of travel at the other of said limits.
 4. The rotary printer of claim 3 and a clutch releasable interconnecting the gear means from the rotatable member.
 5. The rotary printer of claim 3 in which the gear means includes first and second gears of different sizes, one for each rack portion, the blanket portion defines a minor arc, the smaller gear is in engagement with its rack portion during return travel of the carriage and its size is such as to turn the rotatable member of the carriage at a sufficiently increased rate to ensure that the blanket portion is in said starting position at the end of said return travel.
 6. The rotary printer of claim 1 in which the printer includes supporting structure, means connecting the carriage to the structure laterally of the conveyor for movement relative thereto through said predetermined stroke and the member rotating means includes gear means rotatable with the rotatable member of the carriage, a frame mounted on said structure at one side of the conveyor for vertical movement between two limits, first and second rack portions extending lengthwise of the path of the carriage and connected to said frame, means connected to said frame and operable to reciprocate it between said two limits, said rack portions being disposed relative to said gear means for engagement therewith in the alternative, one rack portion in one direction of carriage travel at one of said limits and the other rack portion in the other direction of carriage travel at the other of said limits.
 7. The rotary printer of claim 1 in which the arcuate extent of the blanket portion is such the rotatable member may turn at the same rate in both directions of carriage travel with the blanket portion being in its starting position at the end of the return stroke.
 8. The rotary printer of claim 1 in which there are a plurality of form rolls each of which includes means to deliver Ink thereto and each including a drive connected to the rotatable member, each form roll tangent with the path of said arcuate blanket portion, the form rolls are spaced from each other and so located that said blanket portion is engaged and completely inked by all of them before returning to said starting position.
 9. The rotary printer of claim 1 in which there are a plurality of form rolls each of which includes means to deliver ink thereto and a drive connected to the rotatable member, each form roll tangent to the path of the arcuate blanket portion and the form rolls are spaced from each other and so located that said blanket portion is partially inked by the form rolls during the return of the carriage and the inking of the blanket portion is completed during the printing stroke.
 10. The rotary printer of claim 1 in which there are a plurality of form rolls, each including means to deliver ink thereto, and a drive for the form rolls and the inking means connected to the rotatable member, each form roll tangent to the path of the arcuate blanket portion, the blanket portion includes spaced sections and the form rolls are so spaced from each other and arranged that when the arcuate portion is returned to its starting position, the arcuate portion is completely inked except for its trailing section and the line of tangency of a form roll is between the leading and trailing section.
 11. The rotary printer of claim 1 in which there are a plurality of form rolls, each including means to deliver ink thereto and a drive connected to the rotatable member, each form roll tangent to the path of the blanket portion, the surface to be printed at each dwell includes a plurality of longitudinally spaced zones to be inked, and the blanket portion includes a like number of appropriately spaced and dimensioned zones, the total arcuate extent of the zones of said blanket portion being such that the entire carriage travel in said one direction is required for the printing of the zones of the material present during a dwell, and the form rolls are so spaced from each other and so arranged that when the blanket portion is returned to said starting position the line of tangency of the last form roll to engage said portion is between two zones.
 12. In combination a thermoformer including a heating station, an article forming station, and a blanking station, a conveyor for positively carrying a sheet of a thermoplastic material through said stations in the order named, means to advance said conveyor step-by-step through said stations, a printer adjacent the infeed end of said conveyor but where it is positively advanced thereby and operable to print the sheet before its passage into the heating chamber, and means to operate said printer during a dwell to print that portion of sheet that is to be formed into an article at said forming station, said printer of the rotary type and includes a carriage, means to reciprocate said carriage through a predetermined stroke over said conveyor, said carriage including a rotatable member provided with an arcuate blanket portion engageable with the surface of the sheet of a radius greater than the remainder of said rotatable member, means to rotate said member as an incident of the reciprocation of said carriage but always in the same direction, said carriage also including at least one form roll tangent with the path of said arcuate portion, means to deliver ink to said form roll, and a drive for said form roll and said ink delivery means connected to said rotatable member, said blanket portion in one direction of carriage travel rolling against the surface of the sheet and in the other direction of carriage travel being returned to a predetermined starting position with the printing portion out of the path of the sheet and, by then, at least partially re-inked by rolling engagement with said form roll, said reciprocating means effecting at least said one direction of carriage travel during each dwell.
 13. The combination of claim 12 in which the Member rotating means effects the rotation of said rotatable member in said other direction of carriage travel at a sufficiently higher rate to place the blanket portion in said starting position before the next dwell.
 14. A rotary printer for use in conjunction with a step-by-step conveyor in printing, during dwells, the upper surfaces of thermoplastic sheet material or of articles formed therein, said printer comprising a carriage, means to reciprocate said carriage through a predetermined stroke over said conveyor from a predetermined starting position, and in a return path back to said starting position said carriage including a rotatable member provided with an arcuate blanket portion extending less than 180 degrees around said cylinder rolling against the surface to be printed during travel of the carriage from said position, means to rotate said member as an incident of its reciprocation always in the same direction and effecting the rotation thereof at a sufficiently higher rate in the return travel of the carriage than in said printing travel to place the blanket portion in the same orientation as in said starting position at the end of said return travel, said carriage also including at least one form roll tangent with the path of said arcuate portion, means to deliver ink to said form roll, and a drive for said form roll and said ink delivery means connected to said rotatable member, said blanket portion in said return travel being out of the path of the surfaces and being re-inked by rolling engagement with said form roll, said member rotating means effecting said printing travel during a dwell with said blanket portion in contact with said surface.
 15. The rotary printer of claim 14 in which the printer includes supporting structure, means connecting the carriage to the structure laterally of the conveyor for movement relative thereto through the predetermined stroke and the member rotating means includes gear means rotatable with the rotatable member of the carriage, said means connected to the structure and extending lengthwise of the path of the carriage and shiftable means to effect said different rates of rotation. 